Heres a video Greg(MRRPM) made showing the difference in power by his modded 800cc Rotax up against his 840cc Rotax VS the 1004cc Rotax big bore.
So imagine the difference in the Rhino Rotax Swaps with these kits.
.

Heres a video Greg(MRRPM) made showing the difference in power by his modded 800cc Rotax up against his 840cc Rotax VS the 1004cc Rotax big bore.
So imagine the difference in the Rhino Rotax Swaps with these kits.
.YouTube - MrRPM Horse Power!!!!

WHICH IS FASTEST, A 840 ROTAX VS 840 TERYX? The rex put out 70+ mph with big valves and porting what about the 840 rotax?

Im assuming that most of the 840cc rotax motors that are not pushing fully modded heads are in the mid 60s hp.

My brothers Tyrex 820cc motor built by himself and Dave Maxwell at 2x motorsports, Muzzy exhaust , AFE intake, Dasa intake mod, programable cdi by Dynatek and coils, Vforcejohn clutching, All perfectly tuned and runs on pump gas. It made 59hp on the Wellers dyno. and Jason Weller said his 840 was making 64hp. So maybe a full tilt high compression radical port job big valved, race gas only spining some higher rpms will see 70hp but I dont think there every day 840 will do 70hp. atleast thats what Jason told me.

Im assuming that most of the 840cc rotax motors that are not pushing fully modded heads are in the mid 60s hp.

My brothers Tyrex 820cc motor built by himself and Dave Maxwell at 2x motorsports, Muzzy exhaust , AFE intake, Dasa intake mod, programable cdi by Dynatek and coils, Vforcejohn clutching, All perfectly tuned and runs on pump gas. It made 59hp on the Wellers dyno. and Jason Weller said his 840 was making 64hp. So maybe a full tilt high compression radical port job big valved, race gas only spining some higher rpms will see 70hp but I dont think there every day 840 will do 70hp. atleast thats what Jason told me.

here is a little help, I think. On a car dyno, not sure the maker, my stock 800 dynoed at 52.9 which is what the specs say it should do and 39 on the dyno jet.
my 840 put down 54 on the dyno jet, that's a increaese of 15 rwhp
rick's cat laid down the same # on the dyno jet, so I am assuming I am in the close to 70 rwhp now.

My brothers Tyrex 820cc motor built by himself and Dave Maxwell at 2x motorsports, Muzzy exhaust , AFE intake, Dasa intake mod, programable cdi by Dynatek and coils, Vforcejohn clutching, All perfectly tuned and runs on pump gas. It made 59hp on the Wellers dyno. and Jason Weller said his 840 was making 64hp.

Is it running stock carbs and a stock plenum? If so there is some serious HP to be had by getting rid of the stock carbs and going with some 39's ... then ditch the plenum and run an open intake ontop of the carbs. Soem guys on the teryx forums have done this.

Also no porting right? ..... stock ports on the Teryx are not so hot. There is some more hp to be gained with a mild port job on the teryx.

I would bet with 39's, open intake and mild porting that car would gain 7 - 10 HP on that same dyno .... EASY.

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